Thermostatic circuit closer for laundry irons



I I APPLICATION FILED IULYI6,I9I9. 1,415,829.

. A. E. FITZGERALD. THERMOSTATIC CIRCUIT CLOSER FOR LAUNDRY IRONS.

Patented May 9, 1922.

J32 Uen Z0 417132 2 ger 1 tion.

UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

' THERMOSTATIG orzaoorr cizosna non LAUNDRY IRo s Patented May 9, 1922.

Application filed July 16, 1919. Serial No. 311,287.

T 0 all whom it may concern Beit known that I, ARTHUR ERNEST FITZ-GERALD, a citizen of the Dominion of New Zealand, residing atWellington, inthe Provincial District of Wellington, have in ventedcertain new and useful Improvements in Thermostatic Circuit Closers forLaundry Irons, of which the following is specifica- This inventionrelates to laundry irons heated by electric current, and provided with acoiled switch element mounted in the base forming part of the electriccircuit'of the iron, and adapted to break the circuit when thetemperature reaches a predetermined limit.

The object of the invention is to provide an improved construction ofcontact switch and operating means for the aforesaid purpose and moreparticularly to enable the operating means to be adjusted to the switch,whereby the predetermined maximum limit of temperature of the iron canbe regulated to suit the material on which the iron is to be used. 1

According to the invention the spring switch forms part of the electriccircuit of the iron, and is normally closed.

An operating member which derives its heat from the iron and formedwholly or partly of metal or material adapted to expand under theinfluence of heat is adapted by its expansion to move the switch tocause a break in the circuit within the laundry iron, when apredetermined degree of temperature is reached, whereupon the currentceases to pass and the temperature of the iron falls.

The contraction of said operating member on the temperature recedingpermits the switch to close the break in the circuit and the current toagain pass.

In order to effect the breaking of the circuit at any desired degree oftemperature, the operating member is made adjustable to the switch bymeans of a screw operable from without the iron.

By these means the degree of temperature which it is desired shall notbe exceeded, can be determined before commencing to use the iron, asforinstance, to iron certain material it is found necessary to increasethe temperature, whereupon the operating member is moved by means of theadjusting screw further from the witch or so as to necessitate a higherdegree of temperature being reached before said member will expandsufficiently to operate the switch and cause a break in the circuit.

lVhen a lower temperature isdcsired the operating member is adjustedcloser to the switch or so as to require a lower temperature to causesaid'member to expand suiiiciently in order to operate the switch andeffect a break in the circuit.

The invention will be more particularly described with reference to theaccompanyin drawing, in which *lgure 1 is a plan view of a modificationand Figure 2 a sectional elevation on the line 5--5 Figurel.

Referring to Figures 1 and 2 the operating member is in the form of acoil 18 formed wholly of copper or other similar material or metal, saidcoil 18 being retained in a well 19 of porcelain or other non-conductingand heat resisting material, sunk in the iron base 3.

' The outer end 20 of the coil 18 projects into a recess 21 in theporcelain while the inner end of the coil carries a switch 22 with aterminal 28 thereon kept normally in contact with a terminal 24 on abracket 25 on and insulated from the base 3 and adapted to be put inelectric communication with one of the wires (not shown) of the usualflexible cord of the circuit, the outer end 20 being in practice incontact with one end of the heating element, which is in electriccommunication with the other wire of the afore said flexible cord.

A screw 26 working through a nut 27 contained in the porcelain wall ofthe well 19, is attached to the end 20 of the coil 18,'the head 28 ofsaid screw 26 being located ina recess 29.

Under heat the coil 18 expands at a greater ratio than the wall in whichit is contained and as the outer end 20 is held by the screw 26 theinner end moves and the terminal 23 becomes separated from the terminal24: and the electric circuit is thereby broken to prevent thetemperature exceeding that required.

By adjusting the screw 26 the degree of expansion necessary to operatethe switch 22 to cause a break in the circuit can be increased ordecreased according to the degree of temperature it is desired shall notbe exceeded.

Claims:

1. In an electric laundry iron, a coiled operating member forming partof the circuit by which the iron is heated, a Well oi nonconducting andheat-resisting material containing said coiled member, a contact securedto the inner end of said coil, a bracket Secured on and insulated fromthe base oi said iron, a contact mounted on said bracket and adapted tobe engaged by the contact on said coiled member, and means engaging theouter end of the coiled member for adjusting it Within said Well.

2. In an electric laundry iron including a base formed With a recess, aWell of non-conducting and heat-resisting material mounted in saidrecess, a coiled thermostatic member forming part of the heating circuitof the iron mounted in the recess so that the outer coil has its surfacein contact with the Wall oi? the well, a contact element secured to theinner end oi? the coiled member, a bracket secured on and insulated fromthe base of said iron, a contact mounted on said bracket and adapted tobe engaged by the contact element on said coiled member, and meansengaging the outer end of the coiled member for moving the coil withrespect to the Well.

3. In an electric laundij'y iron, a coiled operating member forming partof the ci1= cuit by which the iron is heated; a- Well of non-conductingand heat resisting material containing said coiled member; a contactsecured to the inner end bracket secured on and insulated from the baseof said iron; a contact mounted on. said bracket and adapted to beengaged by the contact on said coiled member, and a screw for adjustingand holding the outer end of said coiled member, substantially asdescribed and illustrated.

In testin'iony whereof I aliix my sigi'iature.

ARTHUR ERNEST FITZGERALD.

of said coil; a

